English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Recently, Zhong et al. performed landmark Gaussian boson sampling experimentswith up to 144 modes using threshold detectors. The authors claim to haveachieved quantum computational advantage with the implementation of theseexperiments, named Jiuzhang 1.0 and Jiuzhang 2.0. Their experimental resultsare validated against several classical hypotheses and adversaries using testssuch as the comparison of statistical correlations between modes, Bayesianhypothesis testing and the Heavy Output Generation (HOG) test. We propose analternative classical hypothesis for the validation of these experiments usingthe probability distribution of mixtures of coherent states sent into a lossyinterferometer; these input mixed states, which we term squashed states, havevacuum fluctuations in one quadrature and excess fluctuations in the other. Wefind that for configurations in the high photon number density regime, thecomparison of statistical correlations does not tell apart the ground truth ofthe experiment (two-mode squeezed states sent into an interferometer) from ouralternative hypothesis. The Bayesian test indicates that, for allconfigurations excepting Jiuzhang 1.0, the ground truth is a more likelyexplanation of the experimental data than our alternative hypothesis. A similarresult is obtained for the HOG test: for all configurations of Jiuzhang 2.0,the test indicates that the experimental samples have higher ground truthprobability than the samples obtained form our alternative distribution; forJiuzhang 1.0 the test is inconclusive. Our results provide a new hypothesisthat should be considered in the validation of future GBS experiments, and shedlight into the need to identify proper metrics to verify quantum advantage inthe context of GBS. They also indicate that a classical explanation of theJiuzhang 1.0 experiment, lacking any quantum features, has not been ruled out.

Classical models may be a better explanation of the Jiuzhang 1.0 Gaussian Boson Sampler than its targeted squeezed light model